Final answer:
When using a micropipetter, pressing past the first stop point before drawing up a sample results in measuring less liquid than intended, as additional air takes up space meant for the liquid. Precision with the plunger stop points is crucial for accurate measurements.
Step-by-step explanation:
If you push the top button of a micropipetter past its first stop point before drawing up a sample, you will measure less liquid than you intend to. When using a micropipetter, there are typically two stop points in the operation of the plunger. The first stop point is used to draw up the set volume of liquid into the pipette tip. Pushing beyond that to the second stop point usually expels additional air, which is meant to ensure complete dispensing of the liquid when releasing your sample.
Therefore, if you push past the first stop point during the draw-up, you'd be indicating the micropipetter to take in less volume, because part of the capacity meant for liquid will be occupied by additional air.
Using a micropipette correctly requires understanding and being precise with its stop points to ensure accurate measurements when conducting experiments or making dilutions. Always remember to carefully read the volume setting and operate the plunger to the right stop point when drawing up or dispensing liquids.